Develop Reference

Filter Attributes in Xml in c# AND modify the Xml

I am trying to convert and Xml A into Xml B using C#.
XML A
<root>
<country>
<city name="Boston" value="100">
<city name="Boston" value="200">
</country>
</root>
XMl B(Expected)
<root>
<country>
<city name="Boston" value="300">
</country>
</root>
C# code:
var doc = XDocument.Load(path);
var myDocument = new XmlDocument();
myDocument.Load(path);
var nodes = myDocument.GetElementsByTagName("city");
var resultNodes = new List<XmlNode>();
foreach (XmlNode node in nodes)
{
if (node.Attributes != null && node.Attributes["name"] != null && node.Attributes["name"].Value == "Boston")
resultNodes.Add(node);
foreach(var elements in resultNodes)
{
elements.Attributes.RemoveNamedItem("Boston");
}
}
Basically what i wanted to do here is add the 2 values(100 &200)from 2 different Boston attributes from XML A and print into a new XML B file but lost a bit here as what goes into this block.
foreach (XmlNode i in resultNodes)
{
}

Problems like this is easy to create new XElements. See code below :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
namespace ConsoleApplication1
{
class Program
{
const string FILENAME = #"c:\temp\test.xml";
static void Main(string[] args)
{
XDocument doc = XDocument.Load(FILENAME);
List<XElement> countries = doc.Descendants("country").ToList();
foreach (XElement oldCountry in countries)
{
XElement newCountry = new XElement("country");
var cities = oldCountry.Elements("city").GroupBy(x => (string)x.Attribute("name"));
foreach (var city in cities)
{
newCountry.Add(new XElement("city", new object[] { new XAttribute("name", city.Key), new XAttribute("value", city.Sum(x => (int)x.Attribute("value"))) }));
}
oldCountry.ReplaceWith(newCountry);
}
}
}
}

How to Read XML tag values in C# [duplicate]

I am using this XML file:
<root>
<level1 name="A">
<level2 name="A1" />
<level2 name="A2" />
</level1>
<level1 name="B">
<level2 name="B1" />
<level2 name="B2" />
</level1>
<level1 name="C" />
</root>
Could someone give me a C# code using LINQ, the simplest way to print this result:
(Note the extra space if it is a level2 node)
A
A1
A2
B
B1
B2
C
Currently I have written this code:
XDocument xdoc = XDocument.Load("data.xml"));
var lv1s = from lv1 in xdoc.Descendants("level1")
select lv1.Attribute("name").Value;
foreach (var lv1 in lv1s)
{
result.AppendLine(lv1);
var lv2s = from lv2 in xdoc...???
}

Try this.
using System.Xml.Linq;
void Main()
{
StringBuilder result = new StringBuilder();
//Load xml
XDocument xdoc = XDocument.Load("data.xml");
//Run query
var lv1s = from lv1 in xdoc.Descendants("level1")
select new {
Header = lv1.Attribute("name").Value,
Children = lv1.Descendants("level2")
};
//Loop through results
foreach (var lv1 in lv1s){
result.AppendLine(lv1.Header);
foreach(var lv2 in lv1.Children)
result.AppendLine(" " + lv2.Attribute("name").Value);
}
Console.WriteLine(result);
}

Or, if you want a more general approach - i.e. for nesting up to "levelN":
void Main()
{
XElement rootElement = XElement.Load(#"c:\events\test.xml");
Console.WriteLine(GetOutline(0, rootElement));
}
private string GetOutline(int indentLevel, XElement element)
{
StringBuilder result = new StringBuilder();
if (element.Attribute("name") != null)
{
result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
}
foreach (XElement childElement in element.Elements())
{
result.Append(GetOutline(indentLevel + 1, childElement));
}
return result.ToString();
}

A couple of plain old foreach loops provides a clean solution:
foreach (XElement level1Element in XElement.Load("data.xml").Elements("level1"))
{
result.AppendLine(level1Element.Attribute("name").Value);
foreach (XElement level2Element in level1Element.Elements("level2"))
{
result.AppendLine(" " + level2Element.Attribute("name").Value);
}
}

Here are a couple of complete working examples that build on the #bendewey & #dommer examples. I needed to tweak each one a bit to get it to work, but in case another LINQ noob is looking for working examples, here you go:
//bendewey's example using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
class loadXMLToLINQ1
{
static void Main( )
{
//Load xml
XDocument xdoc = XDocument.Load(#"c:\\data.xml"); //you'll have to edit your path
//Run query
var lv1s = from lv1 in xdoc.Descendants("level1")
select new
{
Header = lv1.Attribute("name").Value,
Children = lv1.Descendants("level2")
};
StringBuilder result = new StringBuilder(); //had to add this to make the result work
//Loop through results
foreach (var lv1 in lv1s)
{
result.AppendLine(" " + lv1.Header);
foreach(var lv2 in lv1.Children)
result.AppendLine(" " + lv2.Attribute("name").Value);
}
Console.WriteLine(result.ToString()); //added this so you could see the output on the console
}
}
And next:
//Dommer's example, using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
class loadXMLToLINQ
{
static void Main( )
{
XElement rootElement = XElement.Load(#"c:\\data.xml"); //you'll have to edit your path
Console.WriteLine(GetOutline(0, rootElement));
}
static private string GetOutline(int indentLevel, XElement element)
{
StringBuilder result = new StringBuilder();
if (element.Attribute("name") != null)
{
result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
}
foreach (XElement childElement in element.Elements())
{
result.Append(GetOutline(indentLevel + 1, childElement));
}
return result.ToString();
}
}
These both compile & work in VS2010 using csc.exe version 4.0.30319.1 and give the exact same output. Hopefully these help someone else who's looking for working examples of code.
EDIT: added #eglasius' example as well since it became useful to me:
//#eglasius example, still using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
class loadXMLToLINQ2
{
static void Main( )
{
StringBuilder result = new StringBuilder(); //needed for result below
XDocument xdoc = XDocument.Load(#"c:\\deg\\data.xml"); //you'll have to edit your path
var lv1s = xdoc.Root.Descendants("level1");
var lvs = lv1s.SelectMany(l=>
new string[]{ l.Attribute("name").Value }
.Union(
l.Descendants("level2")
.Select(l2=>" " + l2.Attribute("name").Value)
)
);
foreach (var lv in lvs)
{
result.AppendLine(lv);
}
Console.WriteLine(result);//added this so you could see the result
}
}

XDocument xdoc = XDocument.Load("data.xml");
var lv1s = xdoc.Root.Descendants("level1");
var lvs = lv1s.SelectMany(l=>
new string[]{ l.Attribute("name").Value }
.Union(
l.Descendants("level2")
.Select(l2=>" " + l2.Attribute("name").Value)
)
);
foreach (var lv in lvs)
{
result.AppendLine(lv);
}
Ps. You have to use .Root on any of these versions.

Asynchronous loading of the XML file can improve performance, especially if the file is large or if it takes a long time to load. In this example, we use the XDocument.LoadAsync method to load and parse the XML file asynchronously, which can help to prevent the application from becoming unresponsive while the file is being loaded.
Demo: https://dotnetfiddle.net/PGFE7c (using XML string parsing)
Implementation:
XDocument doc;
// Open the XML file using File.OpenRead and pass the stream to
// XDocument.LoadAsync to load and parse the XML asynchronously
using (var stream = File.OpenRead("data.xml"))
{
doc = await XDocument.LoadAsync(stream, LoadOptions.None, CancellationToken.None);
}
// Select the level1 elements from the document and create an anonymous object for each element
// with a Name property containing the value of the "name" attribute and a Children property
// containing a collection of the names of the level2 elements
var results = doc.Descendants("level1")
.Select(level1 => new
{
Name = level1.Attribute("name").Value,
Children = level1.Descendants("level2")
.Select(level2 => level2.Attribute("name").Value)
});
foreach (var result in results)
{
Console.WriteLine(result.Name);
foreach (var child in result.Children)
Console.WriteLine(" " + child);
}
Result:
A
  A1
  A2
B
  B1
  B2
C

Serializing a list of objects to XDocument

I'm trying to use the following code to serialize a list of objects into XDocument, but I'm getting an error stating that "Non white space characters cannot be added to content
"
public XDocument GetEngagement(MyApplication application)
{
ProxyClient client = new ProxyClient();
List<Engagement> engs;
List<Engagement> allEngs = new List<Engagement>();
foreach (Applicant app in application.Applicants)
{
engs = new List<Engagement>();
engs = client.GetEngagements("myConnString", app.SSN.ToString());
allEngs.AddRange(engs);
}
DataContractSerializer ser = new DataContractSerializer(allEngs.GetType());
StringBuilder sb = new StringBuilder();
System.Xml.XmlWriterSettings xws = new System.Xml.XmlWriterSettings();
xws.OmitXmlDeclaration = true;
xws.Indent = true;
using (System.Xml.XmlWriter xw = System.Xml.XmlWriter.Create(sb, xws))
{
ser.WriteObject(xw, allEngs);
}
return new XDocument(sb.ToString());
}
What am I doing wrong? Is it the XDocument constructor that doesn't take a list of objects? how do solve this?

I would think that last line should be
return XDocument.Parse(sb.ToString());
And it might be an idea to cut out the serializer altogether, it should be easy to directly create an XDoc from the List<> . That gives you full control over the outcome.
Roughly:
var xDoc = new XDocument( new XElement("Engagements",
from eng in allEngs
select new XElement ("Engagement",
new XAttribute("Name", eng.Name),
new XElement("When", eng.When) )
));

The ctor of XDocument expects other objects like XElement and XAttribute. Have a look at the documentation. What you are looking for is XDocument.Parse(...).
The following should work too (not tested):
XDocument doc = new XDocument();
XmlWriter writer = doc.CreateNavigator().AppendChild();
Now you can write directly into the document without using a StringBuilder. Should be much faster.

I have done the job this way.
private void button2_Click(object sender, EventArgs e)
{
List<BrokerInfo> listOfBroker = new List<BrokerInfo>()
{
new BrokerInfo { Section = "TestSec1", Lineitem ="TestLi1" },
new BrokerInfo { Section = "TestSec2", Lineitem = "TestLi2" },
new BrokerInfo { Section = "TestSec3", Lineitem ="TestLi3" }
};
var xDoc = new XDocument(new XElement("Engagements",
new XElement("BrokerData",
from broker in listOfBroker
select new XElement("BrokerInfo",
new XElement("Section", broker.Section),
new XElement("When", broker.Lineitem))
)));
xDoc.Save("D:\\BrokerInfo.xml");
}
public class BrokerInfo
{
public string Section { get; set; }
public string Lineitem { get; set; }
}

How to add another top level node

I have my linq code formatted like:
<Deck>
<Treasure>
<card>
.....
</card>
......
</treasure>
<Door>
<card>
.....
</card>
......
</Door>
In the following code how do I add another Door that is the same "level" as treasure? Everything I have tried keeps adding it as the same level as card. Here is what I have:
public void SaveXml(string path)
{
XElement xml;
XElement root = new XElement("Treasure");
foreach (var item in TreasureCards)
{
xml = new XElement("Card",
new XAttribute("name", item.Name),
new XElement("Type", item.Type),
new XElement("Image",
new XAttribute("path", item.Image)),
new XElement("Usage", item.Usage),
new XElement("Quantity", item.Quantity),
new XElement("Sell", item.Sell)
);
root.Add(xml);
}
root.Add(new XElement("Door"));
foreach (var item in DoorCards)
{
xml = new XElement("Card",
new XAttribute("name", item.Name),
new XElement("Type", item.Type),
new XElement("Image",
new XAttribute("path", item.Image)),
new XElement("Usage", item.Usage),
new XElement("Quantity", item.Quantity));
root.Add(xml);
}

You need to create the Deck element first:
XElement deck = new XElement("Deck");
Then add both the treasure (which i've taken the liberty of renaming from root to treasure) and the door to it:
XElement treasure = new XElement("Treasure")
...
deck.Add(treasure)
...
XElement door = new XElement("Door")
...
deck.Add(door)

How to use XmlSerializer to deserialize a simple collection into an instance of List<string>

I haven't been able to find a question related to my specific problem.
What I am trying to do is take a list of Xml nodes, and directly deserialize them to a List without having to create a class with attributes.
So the xml (myconfig.xml) would look something like this...
<collection>
<item>item1</item>
<item>item2</item>
<item>item3</item>
<item>etc...</item>
</collection>
In the end I would like a list of items as strings.
The code would look like this.
XmlSerializer serializer = new XmlSerializer( typeof( List<string> ) );
using (XmlReader reader = XmlReader.Create( "myconfig.xml" )
{
List<string> itemCollection = (List<string>)serializer.Deserialize( reader );
}
I'm not 100% confident that this is possible, but I'm guessing it should be. Any help would be greatly appreciated.

Are you married to the idea of using a serializer? If not, you can try Linq-to-XML. (.NET 3.5, C# 3 [and higher])
Based on your provided XML file format, this is the simple code.
// add 'using System.Xml.Linq' to your code file
string file = #"C:\Temp\myconfig.xml";
XDocument document = XDocument.Load(file);
List<string> list = (from item in document.Root.Elements("item")
select item.Value)
.ToList();

Ok, interestingly enough I may have found half the answer by serializing an existing List.
The result I got is as follows...
This following code:
List<string> things = new List<string> { "thing1", "thing2" };
XmlSerializer serializer = new XmlSerializer(typeof(List<string>), overrides);
using (TextWriter textWriter = new StreamWriter("things.xml"))
{
serializer.Serialize(textWriter, things);
}
Outputs a result of:
<?xml version="1.0" encoding="utf-8"?>
<ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<string>thing1</string>
<string>thing2</string>
</ArrayOfString>
I can override the root node by passing an XmlAttributeOverrides instance to the second parameter of the XmlSerializer constructor. It is created like this:
XmlAttributeOverrides overrides = new XmlAttributeOverrides();
XmlAttributes attributes = new XmlAttributes { XmlRoot = new XmlRootAttribute("collection") };
overrides.Add( typeof(List<string>), attributes );
This will change "ArrayOfString" to "collection". I still have not figured out how to control the name of the string element.

To customize List element names using XmlSerializer, you have to wrap the list.
[XmlRoot(Namespace="", ElementName="collection")]
public class ConfigWrapper
{
[XmlElement("item")]
public List<string> Items{ get; set;}
}
Usage:
var itemsList = new List<string>{"item1", "item2", "item3"};
var cfgIn = new ConfigWrapper{ Items = itemsList };
var xs = new XmlSerializer(typeof(ConfigWrapper));
string fileContent = null;
using (var sw = new StringWriter())
{
xs.Serialize(sw, cfgIn);
fileContent = sw.ToString();
Console.WriteLine (fileContent);
}
ConfigWrapper cfgOut = null;
using (var sr = new StringReader(fileContent))
{
cfgOut = xs.Deserialize(sr) as ConfigWrapper;
// cfgOut.Dump(); //view in LinqPad
if(cfgOut != null)
// yields 'item2'
Console.WriteLine (cfgOut.Items[1]);
}
Output:
// fileContent:
<?xml version="1.0" encoding="utf-16"?>
<collection xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<item>item1</item>
<item>item2</item>
<item>item3</item>
</collection>
If you don't want to wrap the list, the DataContractSerializer will allow you to custom name the elements if you subclass it:
[CollectionDataContract(Name = "collection", ItemName = "item", Namespace = "")]
public class ConfigWrapper : List<string>
{
public ConfigWrapper() : base() { }
public ConfigWrapper(IEnumerable<string> items) : base(items) { }
public ConfigWrapper(int capacity) : base(capacity) { }
}
Usage And Output:
var cfgIn = new ConfigWrapper{ "item1", "item2", "item3" };
var ds = new DataContractSerializer(typeof(ConfigWrapper));
string fileContent = null;
using (var ms = new MemoryStream())
{
ds.WriteObject(ms, cfgIn);
fileContent = Encoding.UTF8.GetString(ms.ToArray());
Console.WriteLine (fileContent);
}
// yields: <collection xmlns:i="http://www.w3.org/2001/XMLSchema-instance"><item>item1</item><item>item2</item><item>item3</item></collection>
ConfigWrapper cfgOut = null;
using (var sr = new StringReader(fileContent))
{
using(var xr = XmlReader.Create(sr))
{
cfgOut = ds.ReadObject(xr) as ConfigWrapper;
// cfgOut.Dump(); //view in LinqPad
if(cfgOut != null)
// yields 'item2'
Console.WriteLine (cfgOut[1]);
}
}